Amavasai

In Sanskrit, “amā” means “together” and “vásya” means “to dwell” or “cohabit”. It also means “na” +”ma”+”asya” meaning to “na” = “No, “ma”=Moon, “Asya”=”There” in turn meaning to There is no Moon i.e., Moon is not visible.

According to Hindu lunar calendar, the month starts on the day following the full moon or Purnima and therefore Amavasya always falls in the middle of the month. An Amavasya falling on Mondays has a special significance.